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Papers by Albrecht Winnacker

The Physics Behind Semiconductor Technology

Physical Review B, 1972

First, we would like to extend the most profound thanks to Professor C. D. Jeffries for his const... more First, we would like to extend the most profound thanks to Professor C. D. Jeffries for his constant encouragement and support of this work. We also gratefully acknowledge the assistance, at various times in the experiments, of S. Yngvesson, A. %innacker, and G. Baldacchini. And a few of the many other individuals with whom we have had fruitful discussions are W.

電子情報通信学会技術研究報告 Us 超音波, Feb 19, 2008

ChemInform, Feb 3, 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Materials Science Forum, 2001

Tenth Feofilov Symposium on Spectroscopy of Crystals Activated by Rare-Earth and Transitional-Metal Ions, 1996

The physical mechanisms of x-ray storage phosphors are discussed. This includes questions like th... more The physical mechanisms of x-ray storage phosphors are discussed. This includes questions like the nature of the traps involved, the storage and reading process, the time constants involved, the thermal stability of storage, and the sensitivity. Finally some questions related to film preparation and image quality are investigated and the potential of the 'image plates' for various applications are outlined.

Materials Science Forum, 2004

In this work the first PVT grown in-situ erbium doped SiC bulk crystal, to our knowledge, is pres... more In this work the first PVT grown in-situ erbium doped SiC bulk crystal, to our knowledge, is presented. The crystal was characterised by secondary ion mass spectrometry (SIMS) and photoluminescence measurements. SIMS investigations show erbium concentrations in the range of 1.1 · 1014 cm−3 to 2.9 · 1014 cm−3. Photoluminescence measurements between 1450 nm and 1650 nm were conducted at 19 K, 77 K and 300 K. A distinct luminescence at 1540 nm corresponding to the I13/2 → I15/2 transition was detected even at room temperature. In the investigated temperature range, luminescence intensity shows only a slight decrease of 16 %. Measurements with different laser powers suggest a saturation of erbium related luminescence in our experimental conditions.

physica status solidi c, 2012

The effect of terbium (Tb) doping on the photoluminescence (PL) of crystalline aluminum nitride (... more The effect of terbium (Tb) doping on the photoluminescence (PL) of crystalline aluminum nitride (c ‐AlN) and amorphous hydrogenated silicon carbide (a ‐SiC:H) thin films has been investigated for different Tb atomic concentrations. The samples were prepared by DC and RF magnetron reactive sputtering techniques covering the concentration range of Tb from 0.5 to 11 at.%. The Tb‐related light emission versus the Tb concentration is reported for annealing temperatures of 450 °C, 750 °C and 1000 °C. In the low concentration region the intensity exhibits a linear increase and its slope is enhanced with the annealing temperature giving an activation energy of 0.106 eV in an Arrhenius plot. In the high concentration region an exponential decay is recorded which is almost independent on the host material, its structure and the annealing process (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Radiation Measurements, 2007

In CsBr: Eu 2+ the intensities of photoluminescence (PL) and photostimulated luminescence (PSL) s... more In CsBr: Eu 2+ the intensities of photoluminescence (PL) and photostimulated luminescence (PSL) strongly depend on the annealing status of the samples. "As grown" image plates offer only poor PL and PSL output. When the image plates are annealed at temperatures around 450 K, the PL and PSL intensities can be increased by a factor of more than four, but when annealed at temperatures exceeding 470 K, the PL and PSL intensity is lowered again tremendously. This effect might result from fundamental changes in the environment of Eu 2+ ions, which become manifest in the low-temperature luminescence spectra of differently temperature treated samples.

The Physics Behind Semiconductor Technology

Physical Review B, 1972

First, we would like to extend the most profound thanks to Professor C. D. Jeffries for his const... more First, we would like to extend the most profound thanks to Professor C. D. Jeffries for his constant encouragement and support of this work. We also gratefully acknowledge the assistance, at various times in the experiments, of S. Yngvesson, A. %innacker, and G. Baldacchini. And a few of the many other individuals with whom we have had fruitful discussions are W.

電子情報通信学会技術研究報告 Us 超音波, Feb 19, 2008

ChemInform, Feb 3, 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Materials Science Forum, 2001

Tenth Feofilov Symposium on Spectroscopy of Crystals Activated by Rare-Earth and Transitional-Metal Ions, 1996

The physical mechanisms of x-ray storage phosphors are discussed. This includes questions like th... more The physical mechanisms of x-ray storage phosphors are discussed. This includes questions like the nature of the traps involved, the storage and reading process, the time constants involved, the thermal stability of storage, and the sensitivity. Finally some questions related to film preparation and image quality are investigated and the potential of the 'image plates' for various applications are outlined.

Materials Science Forum, 2004

In this work the first PVT grown in-situ erbium doped SiC bulk crystal, to our knowledge, is pres... more In this work the first PVT grown in-situ erbium doped SiC bulk crystal, to our knowledge, is presented. The crystal was characterised by secondary ion mass spectrometry (SIMS) and photoluminescence measurements. SIMS investigations show erbium concentrations in the range of 1.1 · 1014 cm−3 to 2.9 · 1014 cm−3. Photoluminescence measurements between 1450 nm and 1650 nm were conducted at 19 K, 77 K and 300 K. A distinct luminescence at 1540 nm corresponding to the I13/2 → I15/2 transition was detected even at room temperature. In the investigated temperature range, luminescence intensity shows only a slight decrease of 16 %. Measurements with different laser powers suggest a saturation of erbium related luminescence in our experimental conditions.

physica status solidi c, 2012

The effect of terbium (Tb) doping on the photoluminescence (PL) of crystalline aluminum nitride (... more The effect of terbium (Tb) doping on the photoluminescence (PL) of crystalline aluminum nitride (c ‐AlN) and amorphous hydrogenated silicon carbide (a ‐SiC:H) thin films has been investigated for different Tb atomic concentrations. The samples were prepared by DC and RF magnetron reactive sputtering techniques covering the concentration range of Tb from 0.5 to 11 at.%. The Tb‐related light emission versus the Tb concentration is reported for annealing temperatures of 450 °C, 750 °C and 1000 °C. In the low concentration region the intensity exhibits a linear increase and its slope is enhanced with the annealing temperature giving an activation energy of 0.106 eV in an Arrhenius plot. In the high concentration region an exponential decay is recorded which is almost independent on the host material, its structure and the annealing process (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Radiation Measurements, 2007

In CsBr: Eu 2+ the intensities of photoluminescence (PL) and photostimulated luminescence (PSL) s... more In CsBr: Eu 2+ the intensities of photoluminescence (PL) and photostimulated luminescence (PSL) strongly depend on the annealing status of the samples. "As grown" image plates offer only poor PL and PSL output. When the image plates are annealed at temperatures around 450 K, the PL and PSL intensities can be increased by a factor of more than four, but when annealed at temperatures exceeding 470 K, the PL and PSL intensity is lowered again tremendously. This effect might result from fundamental changes in the environment of Eu 2+ ions, which become manifest in the low-temperature luminescence spectra of differently temperature treated samples.